The present invention relates to a radial-piston pump comprising a number of cylinders with their respective axes arranged a given angular distance apart about a drive shaft; a number of pistons, each having an inner radial end, and each sliding inside a respective said cylinder; and a cam for activating said pistons and rotating on an eccentric portion of said shaft.
A pump of the aforementioned type is described in document EP-A-304,743, wherein provision is made for three pistons arranged radially and resting on the cam by means of a spring. As the shaft rotates, however, the piston moves in relation to the surface of the cam, the sliding friction of which results in wear and heat.